Patent GB-546300-A (GB)
Title: Improvements in or relating to sewing machines
IPC: D05B3/14
Filed: 1940-07-09
Abstract: 546,300. Button-attaching machines. JACKSON, L., MELLERSH- (International Button Hole Sewing Machine Co.). July 9, 1940. No. 11443. [Class 112] A work-plate 31 and a button-holding presser-foot 33 are carried by a frame 32 secured to a shaft 36 mounted to rock and slide in lugs 37. The frame is oscillated to distribute the stitches between the two holes of a pair by one or other of two cam tracks 46, 47, a pin cam-follower 44, a lever 42, a link and a slotted quadrant arm integral with a forked arm 39 embracing the part 32a of the frame. The lever 42 is provided with alternative sockets for the pin 44 so that it may be positioned to enter either of the cam tracks 46, 47. The frame is moved longitudinally, to transfer the stitching from one pair of holes to the other in a four-hole button, by a lever 63 having a pin camfollower riding in a cam groove 67, Fig. 5, and engaging a pin 64 on the shaft 36. The pin cam-follower can be withdrawn from the cam and the lever 63 locked in position for the sewing of two-hole buttons. The main shaft 23, Fig. 7, is driven from wheel 76 by means of a pawl 78 which engages in a recess 77 in the wheel. When the stop-lever 81 is tripped, a resilient head 82 moves into the path of the pawl 78 and, in stopping it, removes it from the recess 77 at the same time a latch 86 on the head engages over a tooth 87 and rebound is prevented. The stop-lever 81 is connected by a lever 131 and links 133, 130 to a lever 127, Fig. 3, carrying a spring- pressed latch 125. When the latch plate 126 engages in a notch, such as 122, in a continuously rotating controller 120, it and the lever 127 are dragged to the left and the stop-lever is moved to the stopping position. A fixed pin 135 acting on a surface 134 of the latch removes the latter from the notch. The stop-lever is moved to start the machine by a treadle-gear and lever 84 and a spring pin 88 holds the lever 84 in the stop and start positions. The cam tracks 46, 47 are shaped to provide two and three stitch groups, respectively, each followed by a fastening stitch, for one revolution of the cam and means are provided for stopping the machine one, two, three or four times for each revolution or three times for each two revolutions. The cam 68 can be rotated with the cam tracks 46, 47 or it may make three revolutions for two of the cam tracks. The stopping point is varied by means of two series of notches, one series 121 being in the edge of the controller body 48 and the other, 122, in a disc 120 which can be fixed in any one of four positions by placing a pin 123 in one of the holes A, B, C, D in the disc and a hole 124 in the controller body. With the pin in hole A, as shown, four notches on the discs coincide and are effective to receive the latch plate 126. With the pin in the other holes, two, one and three notches coincide. When the pin is passed through a slot 141 in the disc 120 into a hole 142 eccentrically disposed in the end of a rotating piece 112, the registering of the notches changes as the parts rotate and only three notches are effective in two revolutions. The controller today is driven by a worm 56 and wheel teeth 55. The cam 68 is fixed on a spindle 95 carrying a slidable key 113. As shown, the spindle 95 is keyed to the controller body and rotates with it. By moving a pin 105, the key can be brought to a keyway 107 in the hub of an internally toothed wheel 108 geared through the piece 112 with a fixed pinion 113, the gear ratio being two to three. Specification 526,322 and U.S.A. Specifications 376,364 and 393,766 are referred to.